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Practical Limits of Multijunction Solar Cells
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  • Ian Marius Peters,
  • Carlos Rodríguez Gallegos,
  • Larry Lüer,
  • Jens Hauch,
  • Christoph Brabec
Ian Marius Peters
Helmholtz-Institut Erlangen-Nurnberg fur Erneuerbare Energien

Corresponding Author:[email protected]

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Carlos Rodríguez Gallegos
National University of Singapore Solar Energy Research Institute of Singapore
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Larry Lüer
Friedrich-Alexander-Universitat Erlangen-Nurnberg
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Jens Hauch
Helmholtz-Institut Erlangen-Nurnberg fur Erneuerbare Energien
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Christoph Brabec
Helmholtz-Institut Erlangen-Nurnberg fur Erneuerbare Energien
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Multijunction solar cells offer a path to very high conversion efficiency, exceeding 60% in theory. Under ideal conditions, efficiency increases monotonically with the number of junctions. In this study, we explore technical and economic mechanisms acting on tandem solar cells. We find that these mechanisms produce limitations that are the more pronounced the greater the number of junction is and, hence, limit the ideal number of junctions, as well as the corresponding efficiencies. Spectral variations induce current losses in series-connected tandem solar cells. For Denver, we find that these losses reduce achievable harvesting efficiencies to 51% for non-concentrated light, and that they restrict the ideal number of junctions to less than nine. Independently operated solar cells suffer from optical losses with similar consequences. Optical efficiencies of 99% restrict the ideal number of junctions to below ten, and reduce achievable efficiencies by more than 10%. Only architectures with a sequential cell illumination are more resilient to these losses. Restricting available materials reveals that a sufficiently low band gap for the bottom cell of 0.9 eV or below is expedient to realize high efficiencies. Economic considerations show that five junctions or less are economically ideal for most conceivable applications.
05 Dec 2022Submitted to Progress in Photovoltaics
05 Dec 2022Review(s) Completed, Editorial Evaluation Pending
06 Dec 2022Submission Checks Completed
06 Dec 2022Assigned to Editor
04 Jan 2023Reviewer(s) Assigned
10 Mar 2023Editorial Decision: Revise Minor
13 Apr 20231st Revision Received
18 Apr 2023Submission Checks Completed
18 Apr 2023Assigned to Editor
18 Apr 2023Review(s) Completed, Editorial Evaluation Pending
26 Apr 2023Editorial Decision: Accept